It is known by the state of art to use a so called magnet separator for separation of magnetic material from non-magnetic particles out of a conglomerate of metal scrap. Such a one dimensional process does not any more meet the requirements of today to produce quality-steel from scrap. On the contrary, scrap which should be smelt again must consist of pure magnetic material.
Conglomerates of metal scrap are normally delivered by the industry as waste and contain magnetic and non-magnetic particles as well as other residues. Since interest for further treatment is focused solely on pure metals of one type, e.g. magnetic particles as iron or non-magnetic particles as cooper, recycling enterprises are charged with the task to separate such conglomerates into each component in accordance with their individual material related characteristics. This creates significant problems since individual components of materials contained in the conglomerate are often attached together by adhesive forces to such an extent or by loose connection that a normal magnet sorter cannot clearly separate magnetic from non-magnetic components.
Small non-magnetic particles mostly are still combined with magnetic particles or combined by adhesion and enter together with magnetic parts to a follow-up melting process. Steel obtained from such a material composition does not meet the existing standards for high quality steel since steel quality suffers from such a mixture of different components. In order to meet the standards for high quality steel requested today, scrap released for melting must consist of pure iron and is not allowed to contain non-magnetic particles as cooper, not even in the form of cooper dust.
A clear separation of magnetic and non-magnetic material components is one objective of this invention.
Until now for such separation so called magnet sorters were used. Such magnet separators consist of a conveyer belt of non-magnetic material above which magnets are placed. That apparatus is fed by a conglomerate consisting of metal scrap that contains differing components of metal. Magnets attract magnetic particles and allow only part of the non-magnetic particles to fall into a collection container for residues. This kind of separation of magnetic particles contained in a conglomerate of metal is not sufficient since non-magnetic particles still adhere to magnetic particles in a loose way.
A known embodiment recommends for such handling to transport a conglomerate of metal scrap by using a conveyer belt, the belt of which is guided at both ends across deflection pulleys. In the space between the upper trunk and lower trunk of the conveyer belt close to the lower part of the conveyer belt magnets are arranged in a row one following the next one. These magnets may be activated and deactivated intermittingly. This known dry separating machine for non-magnetic particles out of a conglomerate of metal scrap does not meet anymore the existing requirements. That conglomerate of metal scrap is guided along a row of magnets, nonetheless the conglomerate of metal scrap is not sufficiently kept in motion along the conveyer belt (DE Patent specification 311 387), to enable separation of magnetic particles from non-magnetic particles, even though additional means may be attached to the conveyer belt. Pole orientation at this known embodiment is chosen in the following way that a south pole is subsequently followed by a north pole and so on. In this way a permanent change between south and north pole no real motion is achieved, however such a change in pole direction does not result in sufficiently needed motion to separate a conglomerate of metal scrap. Such an orientation of magnets north-south only creates an insufficient motion of the conglomerate of metal scrap transported by the conveyer belt, if any motion at all is reached.